I did, many times. :) Could you please give us output of the command
rpm -qa *xulrun* *firefox* *mozilla* *flash* *plugin*
Please also install firefox-debuginfo (debuginfo-install is from
yum-utils package).
debuginfo-install firefox
Then run firefox with a parameter -g. That will start firefox running inside of gdb debugger. Then use command run and do whatever you did to make firefox crash. When it happens, you should go back to the gdb and run
(gdb) thread apply all backtrace
This produces usually many screens of the text. Copy all of them into a text editor and attach the file to the bug as an uncompressed attachment.
We will review this issue again once you've had a chance to attach this information.
Thanks in advance.

Created attachment 334208[details]
Output from "rpm -qa" and "firefox -g"
Extra info as requested - but as before. The "firefox" command terminates normally well before the crash occurs. So again I have included the output from "gdb /usr/lib/firefox-3.0.6/firefox" just in case that helps.

There were * characters around these names:
rpm -qa *xulrun* *firefox* *mozilla* *flash* *plugin*
Could you please try once more? Do you use flash-plugin from the Adobe yum repository, and do you have nspluginwrapper installed?

i) If '*' required, then output in the attachment. If not, then refer to Comment #1.
ii) flash: "grep -i flash /var/log/rpmpkgs" does not produce anything. Neither is there any "flash" in "yum list available" output. *BUT* I do not have the Adobe repository defined. Should I have flash-* installed?
iii) "nspluginwrapper":
$ grep nspluginwrapper /var/log/rpmpkgs
nspluginwrapper-1.3.0-2.fc10.i386.rpm
nspluginwrapper-debuginfo-1.3.0-2.fc10.i386.rpm
Cheers,
Kevin